I am asking for suggestions for books dealing with the founding fathers of the USA, presidents and other persons of historical significance to our fledgling country as well as the various wars up to and including the Civil War. I am interested in historical as well as biographical works as well as philosophical treatise related to democracy and republicanism. I am not interested in fictional stories or books that are purely modern opinion pieces.

I already have the primary works of Alexis de Tocqueville, John Locke, Adam Smith, Thomas Paine, Socrates and Plato.

I like Patriots  by A.J. Langguth as the best, most accessible overview I have read.  It would make a good text for a advanced HS or college course.  It would make a good first read and opens up lots of doors for good followup on various points of interest.

Benjamin Franklin Biography.

From the "Shameless Plug" department, my Mom's book:

https://www.amazon.com/Letters-Virtue-Civil-Journey-Courage-ebook/dp/1610055209/ref=sr_1_2?ie=UTF8&qid=1475446518&sr=8-2&keywords=Letters+to+Virtue

One of the reviews:

"I find "Letters to Virtue" to be an outstanding historical accounting of the reality and deprivation of war.  Charles Sherman, the real author,
speaks from the grave and his story is right up there with "Killer Angels," a Civil War novel which is mandatory reading for US Army Officers
today.  Every battle has lessons learned, and Sherman provides great insight which leaders of men must grasp to be effective. But more
than Sherman's words,  Ann Gunnin's four year labor of love researching, footnoting and historical validation of Sherman's soldiering until his courageous death makes this an enthralling read. In fact, I was saddened that such a caring, righteous and patriotic man wasn't able to return home to Virtue.  Colonel Robert A Reitz ,  Infantry (Retired)"

The Federalist Papers, if you don't already have them.

A good biography of Thomas Jefferson.  I have four or five.  Yeah, don't know what that says about me.

The best, IMHO, is Dumas Malone's six volume set, written in the 1940's.  Incredible scholarship from original sources and eloquent, clear writing style.  Yes, I said six volumes.

More current and well-done:

David McCullough's bio of John Adams.

Joseph Ellis's bio of George Washington.

For the later post revolutionary war period, military bios, I recommend the autobio of Grant and the entire series, "Lee's Lieutenants" by D.S. Freemam or, better yet, Freeman's R.E. Lee.  Both are multi-volume sets.